- Oct 4 Francesco Crispi, Italian statesman, born in Ribera, Italy (d. 1901)
- Oct 6 Joseph Rummel, German pianist, and composer, born in Wiesbaden, Hesse, The German Confederation (d. 1880)
- Oct 8 John Henninger Reagan, American Confederate politician, born in Sevier County, Tennessee (d. 1905)
- Oct 15 Irvin McDowell, American Major General (Union Army), born in Columbus, Ohio (d. 1885)
- Oct 15 Johann Gungl, Austrian composer and conductor, born in Zsambék, Austrian Empire (d. 1883) (alternatively born March 5 1828)
- Oct 18 Edward Otho Cresap Ord, American engineer and Major General (Union Army), born in Cumberland, Maryland (d. 1883)
- Oct 22 Leconte de Lisle, French poet and writer, born in Saint-Paul, Réunion, France (d. 1894)
- Oct 25 Pavel Melnikov, Russian historian and author (In the Forests) [NS=Nov 6], born in Nizhny Novgorod, Russian Empire (d. 1883)
- Oct 26 Stefano Golinelli, Italian pianist and composer, born in Bologna, Italy (d. 1891)